1. Field of the Invention
The present invention relates to a process for preparing alkyd resins from straight chain, inner epoxyalkanes, which resins yield a hardened product having an excellent resistance to hydrolysis.
2. Description of the Prior Art
It is well known that alkyd resins are obtained by reacting dicarboxylic acids such as phthalic anhydride with polyhydric alcohols such as glycerol. Alkyd resins, modified with oils, that have the alkyd resin skeleton with fatty acid ester side chains, are used widely for the production of hardenable substances for coatings. However, due to the easily hydrolyzable fatty acid ester bonds in the side chain, the hardened product still has insufficient properties such as poor alkali resistance. As alkyd resins free from chemical instability in the side chain that causes the above-mentioned disadvantage, ther have been known alkyd resins obtained from glycidyl esters of monocarboxylic acids having a side chain in the .alpha.-position (Japanese Patent Publication No. 20998/1963), saturated monoalkyl-substituted ethylene glycols (aliphatic 1,2-glycols) (U.S. Pat. No. 3,108,089) and aliphatic 1,2-epoxy compounds (Japanese Patent Publication No. 20360/1966) used in place of the monoglyceride, as a structural unit of the oil-modified alkyd resins. Even though the instability in the side chain, i.e., the disadvantage of the first-mentioned oil-modified alkyd resins, is eliminated by those processes, the resistance of the latter resins to hydrolysis, such as resistance to an alkali or to boiling water, still is unsatisfactory, because the alkyd main chain still contains many primary alkyl ester groups.